On-board diagnostics (OBD) is an automotive industry term referring to a vehicle's self-diagnostic and reporting capability. OBD systems give the vehicle owner or repair technician access to the status of the various vehicle subsystems. The amount of diagnostic information available via OBD has varied widely since its introduction in the early 1980s versions of on-board vehicle computers. More recent OBD implementations use a standardized digital communications port to provide real-time data in addition to a standardized series of diagnostic trouble codes (DTCs), which allow one to rapidly identify and remedy malfunctions within the vehicle.
OBD-II is a current standard that specifies the type of diagnostic connector and its pinout, the electrical signaling protocols available, and the messaging format. It also provides a candidate list of vehicle parameters to monitor along with how to encode the data for each. There is also a pin in the connector that provides power from the vehicle battery for scan tools which are connected to the OBD-II port, which eliminates the need to connect a scan tool to a power source separately.
Modern vehicles are equipped with multiple systems and various sensors used in those systems. The modern automobile may have as many as 70 electronic control units (ECU) for various systems and subsystems. Typically the biggest processor is the engine control unit. Others are used for transmission, airbags, antilock braking/ABS, cruise control, electric power steering, audio systems, power windows, doors, mirror adjustment, battery and recharging systems for hybrid/electric cars, to name a few. Some of these systems are completely independent, but communications among others may exist.
A controller area network (CAN bus) is a vehicle bus standard designed to allow microcontrollers and devices from these various systems and subsystems to communicate with each other without a host computer. It is a message-based protocol, designed originally for multiplex electrical wiring within automobiles, but is also used in many other contexts. Development of the CAN bus started roughly in 1983 at Robert Bosch GmbH. The protocol was officially released in 1986 at the Society of Automotive Engineers (SAE) congress in Detroit, Mich.
An OBD port provides an access port to the OBD system which in turn is connected to the CAN bus and thus communication with the varying systems, subsystems, and sensors (and access to some sensor data) within a vehicle is possible.
Humans and animals may be left inside a vehicle when the vehicle is parked. This has been an issue with parked vehicles practically since the inception of the first vehicles, but even more so as vehicles started to have enclosed cabins. In 1910, Cadillac became the first company in North America to offer a passenger car with a fully enclosed cabin. Vehicles are not currently, nor have ever been, equipped with systems to identify if a human or animal is left inside a parked vehicle. Even if solutions have been developed or proposed to identify humans and animals which may be left inside a parked vehicle, there is also no known solution for the already existing vehicles on the road today. The following disclosure solves this long felt need.